Optical disk driving with inertial damping spring supporting lens holder

Abstract

An optical disc driving device for use in an optical disc apparatus is equipped with an objective lens, a lens holder for holding this lens, and upper and lower support springs for supporting the lens holder. Each support spring consists of a pair of conductive springs which are electrically separated from each other in a plane. Each pair of conductive springs includes straight spring sections extending straight to pass a central axis which is parallel to the optical axis of the lens holder and which passes the center of gravity of the same. End portions of these conductive springs are joined to the lens holder by means of rubber members.

What is claimed is: 
     
       1. An objective lens driving device comprising: an objective lens; a movable device section including a lens holder for holding the objective lens and equipped with focussing coils for moving the objective lens in the direction of the optical axis thereof and tracking coils for rotating the objective lens in a plane substantially perpendicular to the optical axis; magnetic circuits opposed to said focussing coils and said tracking coils; and upper and lower support springs of substantially the same configuration which support said lens holder and each of which consist of a pair of conductive springs electrically separated from each other in a plane, each of said conductive springs having a longitudinal axis which extends radially from a center of gravity axis of said movable device section.   
     
     
       2. An objective lens driving device according to claim 1, wherein said tracking coils are operatively arranged to rotate said movable device section about said center of gravity axis. 
     
     
       3. An objective lens driving device comprising: an objective lens; a movable device section including a lens holder for holding the objective lens and equipped with focusing coils for moving the objective lens in the direction of the optical axis thereof and tracking coils for rotating the objective lens in a plane substantially perpendicular to the optical axis; magnetic circuits opposed to said focussing coils and said tracking coils; and an upper and a lower support springs of substantially the same configuration and arranged parallel to each other which support said lens holder and each of which consists of a pair of conductive springs electrically separated from each other in a plane, each of said conductive springs having a longitudinal axis which extends radially from a center of gravity axis of said movable device section, end portions of each pair of conductive springs being connected to each other by an insulating connecting member.   
     
     
       4. An objective lens driving device as claimed in claim 3, wherein said connecting member is formed of a material having a vibration damping characteristic. 
     
     
       5. An objective lens driving device as claimed in claim 3, wherein bent sections are provided in those portions of said pair of conductive springs. 
     
     
       6. An objective lens driving device according to claim 3, wherein said tracking coils are operatively arranged to rotate said movable device section about said center of gravity axis. 
     
     
       7. An objective lens driving device comprising: an objective lens; a movable device section including a lens holder for holding the objective lens and equipped with focussing coils for moving the objective lens in the direction of the optical axis thereof and tracking coils for rotating the objective lens in a plane substantially perpendicular to the optical axis; magnetic circuits opposed to said focussing coils and said tracking coils; and upper and lower support springs of substantially the same configuration for supporting said lens holder and each consisting of a pair of conductive springs electrically separated from each other in a plane, each of said conductive springs having a longitudinal axis which extends radially from a center of gravity axis of said movable device section, and at least one of said upper and lower support springs being equipped with an adjustment means for effecting fine adjustment of its relative position with respect to the other support spring so as to set said optical axis perpendicular to a disc plane.   
     
     
       8. An objective lens driving device according to claim 7, wherein said tracking coils are operatively arranged to rotate said movable device section of about said center of gravity axis. 
     
     
       9. An objective lens driving device comprising: an objective lens; a lens holder serving to hold the objective lens and equipped with focusing coils for moving the objective lens in the focusing direction to control the distance between the objective lens and an optical disc and tracking coils for moving the objective lens in the tracking direction to control the objective lens such as to follow any eccentricity in the information track of said optical disc; magnetic circuits opposed to said focussing coils and said tracking coils; and support springs for supporting said lens holder; said support springs consisting of a pair of conductive springs each having a longitudinal axis which extends radially from a center of gravity axis of said lens holder, said support springs being joined with said lens holder at the center of gravity axis portion by insulating connecting members, and said tracking coils and said focusing coils being electrically connected to end portions of said conductive springs.   
     
     
       10. An objective lens driving device as claimed in claim 9, wherein said connecting member is formed of a material having a vibration damping characteristic. 
     
     
       11. An objective lens driving device as claimed in claim 9, wherein bent sections are provided in those portions of said pair of conductive springs. 
     
     
       12. An objective lens driving device, according to claim 9, wherein said springs comprise straight spring sections which form a V-shaped. 
     
     
       13. An objective lens driving device according to claim 9, wherein said tracking coils are operatively arranged to rotate said objective lens about said center of gravity axis. 
     
     
       14. Apparatus for supporting a lens holder, comprising a pair of conductive springs separated from each other in a plane, each of said springs having a longitudinal axis which extends radially from a center of gravity axis of the lens holder. 
     
     
       15. The apparatus according to claim 14, wherein the lens holder is part of a movable device section. 
     
     
       16. In a method of rotating an objective lens in a plane substantially perpendicular to the optical axis, the step of rotating said lens about a center of gravity axis of said lens using conductive springs attached to the lens and separated from each other in a plane, each of said springs having a longitudinal axis which extends radially from a center of gravity axis of the lens holder. 
     
     
       17. In the method according to claim 16, wherein the lens is part of a movable device section which includes a lens holder for the lens, and the step of rotating comprises rotating said movable device section in a plane substantially perpendicular to the optical axis about a center of gravity axis of said movable device section. 
     
     
       18. An objective lens driving device having a movable device section with a lens holder, the improvement comprising: upper and lower support springs of substantially the same configuration for supporting the lens holder of each of which consist of a pair of springs separated from each other in a plane, said springs each having a longitudinal axis which extends radially from a center of gravity axis of a movable device section including said lens holder.   
     
     
       19. An objective lens driving device having a movable device section with a lens holder according to claim 18, further comprising focusing coils for moving the objective lens in the focusing direction to control the distance between the objective lens and an optical disk; and tracking coils for moving the objective lens in the tracking direction to control the objective lens such as to follow any eccentricity in the information track of said optical disk. 
     
     
       20. On objective lens driving device having a movable device section with a lens holder according to claim 19, further comprising magnetic circuits opposed to set focusing coils and said tracking coils. 
     
     
       21. An objective lens driving device having a movable device section with a lens holder according to claim 18, wherein said springs are electrically conductive springs.